Apparatus for spinning synthetic-resin filaments

ABSTRACT

An apparatus for spinning synthetic-resin filaments has a distributing head formed with a conical passage into the apex of which a synthetic-resin melt is forced from a worm-type extruder machine. A manifold below the distributing head has a plurality of passages equispaced around the annular mouth constituting the base of the conical passage and each provided with a spinneret or nozzle having a plurality of filament-forming orifices. A stream of cooling air is directed along filaments in their direction of travel away from the spinnerets by an annular air guide surrounding each spinneret or surrounding all the spinnerets.

United States Patent [191 Balk 11] 3,824,050 1 July 16, 1974 1 APPARATUS FOR SPINNING SYNTHETIC-RESIN FILAMENTS [75] Inventor: Hermann Balk, Troisdorf, Germany [73] Assignee: Reifenhauser KG, Troisdorf,

Germany [22] Filed: Mar. 16, 1972 [21] Appl. No.: 235,197

[30] Foreign Application Priority Data Mar. 19, 1971 Germany 2113327 [52] US. Cl. 425/72, 425/382.2 [51] Int. CL... D0ld 3/00 [58] Field of Search 425/72, 381.2, 382, 382.2, 425/382 N, 464; 264/176 F [56] References Cited UNITED STATES PATENTS 1,934,618 11/1933 Briggs et a1. 425/72 X 2,032,606 3/1936 Whitehead 425/72 X 2,923,970 2/1960 Genovese 425/464 1/1962 Gagne 425/464 X 3,016,568 3,366,722 l/l968 Tessier 3,655,314 4/1972 Lenk et al 425/382.2 X

Primary ExaminerRobert D. Baldwin Attorney, Agent, or Firm-Karl F. Ross; Herbert Dubno 57 ABSTRACT An apparatus 'for spinning synthetic-resin filaments has a distributing head formed .with a conical passageinto the apex of which a synthetic-resin melt is forced from a worm-type extruder machine. A manifold below the distributing head has a plurality of passages equispac ed around the annular mouth constituting the base of the conical passage and each provided with a spinneret or nozzle having a plurality of filamentforming orifices. A stream of cooling'air is directed along filaments intheir direction of travel away from the spinnerets by an annular air guide surrounding each spinneret or surrounding all the spinnerets.

4 Claims, 4 Drawing Figures PATENIEDJUH51974 3.824.050

SHEET 1 (IF 2 I APPARATUS FOR SPINNING SYNTHETIC-RESIN I FILAMENTS FIELD OF THE INVENTION The present invention relates to an apparatus for the melt-spinning of synthetic-resin or like hardenable materials into filaments. More particularly this invention concerns an apparatus for this purpose which is mounted on a worm-type or screw-type masticator, plastifier or extruder for spinning a synthetic-resin melt into a multiplicity of monofilaments.

BACKGROUND OF THE INVENTION In order to form some synthetic-resin yarns it has been necessary heretofore to liquefy a synthetic resin, with cooling, so thatthe filaments can be gathered and twisted to form a sliver, roving, yarn or thread of the desired strength and weight.

One particularly useful method. involves the plastification of a resin by means of screws or worms, i.e.', by the use of heat and pressure. The machine is fitted with a manifold in the form of a T with the shank of the T being secured to the outlet opening and a plurality of spinnerets being fixed along the arms of the T. An appropriate network of passages is provided within the manifold for fluid flow to all of the spinnerets along the resulting elongated beam. Y Such an arrangement has some significant disadvantages: for example, it is difficult and time consuming to disassemble the T-manifold and then clean it, and if the device is taken apart it is seldom possible to do a complete cleaning. The pressure of the melt as it arrives at the various spinnerets is not uniform so that filaments of differing characteristicsare produced by different spinnerets. Finally when theremosetting resins are used the curing time will be different for the filaments of each spinneret since the distance the melt has traveled to each spinneret is different.

In addition it is necessary to cool the jets of liquid produced by the spinnerets in order to harden them into stable filaments. This operation has been executed by blowing a current of cool air across the outlets of the spinnerets. This cross current can, and often does, break the delicate filaments of liquid. Italso makes starting of the apparatus difficult since the filaments once formed must be painstakingly threaded to the takeup device.

OBJECTS OF THE INVENTION It is an object of the present invention to provide an improved melt-spinning apparatus whereby the afore mentioned disadvantages are avoided.

Another object is the provision of such an apparatus which can be connected to the outlet of a screw or worm extruder or plastifying machine in order to produce synthetic-resin filaments.

A further object is to provide a melt-spinning apparatus which overcomes the above-given disadvantages of the prior-art systems, and ensures a common history for all equivalent cross sections of the synthetic resin material reaching the nozzles.

SUMMARY OF THE INVENTION I attain the above objects according to the present invention with a melt-spinning apparatus comprising a distributing head having an inlet opening that is mounted over the outlet of the injectiondevice. This head also has an annular outlet opening which communicates with an annular array of spinnerets through a plurality of passages in a manifold fitted over the head. In'addition means is provided to direct a current of cooling air closer the jets as they emerge from the spinneret, this current being in the direction of travel of the filament from the jet. In other words the filament and the coolant move in concurrent flow (uniflow) during the heat-exchange procss.

According to further features of the present invention the outlet orifice of the distributing head is'circular, and the passages and spinnerets arranged therein are equispaced in a circular array in line with this circular orifice. v

With such an arrangement an extremely smallunit can be provided with a relatively large number of spinnerets. Since the distance from the inlet of the head is the same to each spinneret there is no problem of the filaments being different from different spinnerets. This is achieved by forming the channel'through the head as a right-circular cone with the inlet at the apex and the outlet orifice at the base and by providing the'passages all parallel to each other or lying on a frustum coaxial with the cone. This ensures that the path from the outlet of the injection machine is completely identical to each of the spinnerets to give the utmost uniformity in outputs.

Blowing in line with the spinneret jets is achieved by providing either a single large annular nozzle surrounding all of the jets, in which case a conical body between the jets aids in shaping the air stream, or by providing one such annular air nozzle at each spinneret. Ifthe above-described apparatus is centered on 'a vertical axis the filament takeup device may be provided below it, to produce a perfectly symmetrical processing giving a very high quality roving or yarn. Starting up the device is no difficulty as the free ends of the first filaments to be formed will naturally be led by the air current and gravity to the takeup station located beneath. Since the cooling air flows in the same'direction as the filamentforming resin jets, high gas speed can be used for fast cooling and hardening. Similarly, the faster the cooling the greater the production rate, so that stoppages caused by hardening in the spinnerets can be almost v completely avoided.

' DESCRIPTION OF THE DRAWING SPECIFIC DESCRIPTION The spinning apparatus comprises a spinning head 1 carrying eight spinnerets 2 associated with a coolingcuring device 3 and a yam takeup arrangement 4.

More particularly this apparatus comprises 'a distributing head 5 having an upper section 5a adapted to be secured to the extrusion head or outlet 9 of a screw or worm type plastifier. This upper section is formed with anaxial bore 10, relative to a vertical axis A about which the device 1 is symmetrical, which receives melted synthetic resin from the injection head 9. This bore 10 opens into the apex of a conical seat 5b formed in the section 5a. The head 5 also comprises a lower section 5c which is basically conical, matching the seat 5b, but slightly smaller to define a conical passage 6 with the seat 5b. The base of the section 50 is formed with a cylindrical projection 5d received within a collar 7a of a manifold body 7. This manifold '7 is itself formed with eight bores 8, equispaced around the conicalpassage 6 and formed with enlarged upper ends 8a and small circular lower ends 8b. Each end section 8b opens immediately above a spinneret 2 and is parallel to axis A. i

A plate 7b is secured to the bottom of the manifold 7 and carries the eight spinnerets 2 which i in turn formed with eight tiny orifices 2a, so that the spinning unit 1 produces a 64-strand yarn.

The melt is forced down through the passages 10, 6, and 8 to the spinnerets 2 and is there extruded as 64 minute mono-filaments 13, the synthetic resin of each filament 13 having traveled just as far from the upper inlet of the passage 10 as the resin in every other filament 13' for perfectly uniform results. These filaments 13 all are extruded parallel to the surface of a vertical generally conical guide 14 which is made of sheet metal an is secured to the plate 7b.

Surrounding the spinnerets 2 are a pair of annular lips 12a' and 12b defining an annular mouth 12c opening parallel to the conical guide 14, but outwardly of the spinnerets 2. A blower 3a is connected via a manifold 3b to these lips 12a and 12b to force cooling air out of the mouth 12c in order to cool and cure the filaments 13. Since the air flows in the same direction out being subjected to any transverse or lateral forces which might tend to distort them or otherwiseharm them.

FIG. 4 shows how a conventional spinning pump 11 can be provided in each passage 8 to increase the flow rate from the spinnerets. The pumps 11 are carried on a flange 70 formed on the body 7. In addition each spinneret is surrounded by an individual pair of annular lips 15a and 15b defining a mouth 15c around each spinneret 2. No guide 14 need be provided and a manifold 3b interconnects all of the lipslSa and 15b. In this arrangement as in the arrangement of FIGS. 1-3, the air currents tend to keep the filaments 13 in line, and lead them away from their spinnerets.

Located below the unit 1 and axially in line with it is a collar 4a into which all of the filaments 13 are fed. At the lower end of this collar 4a the united and fully cooled filaments 13 are taken up by rollers 4b and thence fed as rovings or sliver between rollers 40 into wheeled hoppers or cans 4d. This roving can later be stretched and twisted to form 64-ply thread.

In order to clean such an apparatus the manifold 7 and head 5 need merely be separated along the line 16,

35 as the filaments 13 these filaments will be cooled withand then the section 5c of the head 5 freed from the manifold 7. Thisdisassembly gives easy access to all of the various passages to allow their cleaning. In particular the passage 6 is thus presented as a pair of conical surfaces that can be easilywiped off, while the spinnerets 2 can be removed and any hardened material in the passages 8 can be knocked out. The passage 10 is similarly easy to clean.

The entire unit 1 is of extremely reduced dimensions, yet it produces sixty-four filaments all having identical properties. No one filament is younger or more cured than any other filament The amount of travel for the syntheticresin making up any one filament-is the same from the injection-molding machine outlet to the takeup reelers as that travel for any other filament.

Manufacture of the unit 1 is quite simple since there are no complicated crossing and matching manifold bores which must be machined and thereafter plugged. Simple machining techniques produce the four major pieces 5a, 5b 7, and 7b thatmake up this unit 1.

I claim:

1. An apparatus for spinning filamentsfrom a pressurized and melted synthetic-resin, said apparatus comprising:

a distributing head formed with an inlet for receiving said resin and an outlet of annular configuration;

a plurality of spinnerets each having a plurality of orifices and each arranged at said other end of a respectiveone of said passages, whereby the melted resin passes through said head and through said manifold and out of said orifices as a plurality of converging jets; and

an inner conical guide core surrounding at least some of said orifices and converging in the direction of convergence of said jets;

an-outer conical guide sleeve coaxially surrounding said guide core and defining an annular gap therewith opening in said direction; and

means for feeding cooling gas to said gap and into heat exchanging relationship with the strands formed by the jets of the orifices surrounded by said core for hardening same into filaments.

2. The apparatus defined in claim 1 wherein said conical guide core surrounds all of said orifices.

3. The apparatus defined in claim 1 wherein a respective such core surrounds the orifices of each of said spinnerets and is, in turn, surrounded by a respective guide sleeve.

4.'The apparatus defined in claim 1, further comprising a cone surrounded by said spinnerets, said spinnerets being disposed in an annulus between said guide 

1. An apparatus for spinning filamenTs from a pressurized and melted synthetic-resin, said apparatus comprising: a distributing head formed with an inlet for receiving said resin and an outlet of annular configuration; a manifold secured to said head over said annular outlet and having a plurality of passages spaced around said annular outlet each having one end communicating with said outlet and another end turned away from said head; a plurality of spinnerets each having a plurality of orifices and each arranged at said other end of a respective one of said passages, whereby the melted resin passes through said head and through said manifold and out of said orifices as a plurality of converging jets; and an inner conical guide core surrounding at least some of said orifices and converging in the direction of convergence of said jets; an outer conical guide sleeve coaxially surrounding said guide core and defining an annular gap therewith opening in said direction; and means for feeding cooling gas to said gap and into heat exchanging relationship with the strands formed by the jets of the orifices surrounded by said core for hardening same into filaments.
 2. The apparatus defined in claim 1 wherein said conical guide core surrounds all of said orifices.
 3. The apparatus defined in claim 1 wherein a respective such core surrounds the orifices of each of said spinnerets and is, in turn, surrounded by a respective guide sleeve.
 4. The apparatus defined in claim 1, further comprising a cone surrounded by said spinnerets, said spinnerets being disposed in an annulus between said guide core and said cone. 